Hi I have this problem with my Nissan, it is a Sentra 2001 GXE
automatic 1.8L, with 140000km on it.

I am very tempted to change the AT fluid and filter, it was already
done twice i think, once by a mechanic at 60 or 80K don't remember,
the second time was by me at 110K-120K(just the fluid). Before i did
my change The RPM at idel were around 1KRPM, once i changed it went
down to 0.6-0.7 KRPM, just like when she was new.
anyway that's aside from the point.

Now this time it is how to describe, jerky, when on plain road with
pedal depressed just enough to keep the 60 or 70km/hr the car feels
like it is jerking, ever so slightly back and forth. Oh i know how to
describe, when you puke, you get this convolging "bua, bua, bua" and
then splat. but less apperant. it goes away if i give it more gas, or
remove my foot from the pedal.
it is felt more and more by the passing months.

I was trying to think what it can be, possibly dirty throttle or
channels, fuel injectors or fuel pressure, idle control, transmission.

The other problem now is that the OD does not kick in untill past65km/
hr, which is strange, it causes high reving period before it goes to
higher gear.
Anyway my plan for a quick fix is to change the trans fluid. I added a
small bottle of trans cure fluid, but i don't think it is doing
anything.

Please anyone any experience or ideas what this could be?
thanks in advance